I can’t help wondering if the name of this hill implies that it was supposedly thrown from somewhere – pick or peck are apparently both old words for pitching or throwing, and the hill is known by both versions. Maybe thrown from Knap Hill or somewhere else along the nearby escarpment? This is pure unfounded speculation but the shape of the hill cries out for a mythological explanation. It seems a natural inspiration for a barrow or even for Silbury.
On second thoughts, I suppose the name sounds a bit like ‘peaked hill’.